4-Amino-5-(6-chloropyridin-3-yl methyl)-4H-1,2,4-triazole-3-thiol has been synthesized and was converted into 3-(6-chloropyridin-3-yl methyl)-6-(4-substituted-phenyl)-7H-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazines and(6-chloropyridin-3-yl­methyl)-6-(4-substituted-phenyl)-7H-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazoles. The newly synthesized compounds are characterized on the basis of elemental analysis, IR, 1H NMR and mass spectral data. Some of the compounds are screened for their antibacterial and insecticidal activities.